JP2003294449A - Driving unit for vibration type angular velocity sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means for reducing an unevenness of a sensor sensitivity due to a change of sensitivity caused by a temperature change and an unevenness of a resonance frequency of a vibrator. <P>SOLUTION: A driving unit for a vibration type angular velocity sensor comprises: a drive force applying means for vibration-driving a vibration element; a drive displacement detecting means for detecting a displacement vibrated by receiving a force of the drive force applying means by the element; a drive signal generating means having an amplitude regulating means for controlling a drive signal output by the drive fore applying means base don a displacement signal detected by the drive displacement detecting means; and an angular velocity detecting means for detecting a displacement in the angular velocity detecting direction of the element by a Coriolis force. In this drive unit, the drive amplitude is controlled so that the ratio of the drive frequency of the element driven by the drive force applying means to the drive amplitude becomes constant. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive circuit of a vibration type angular velocity sensor for driving a vibrator of a vibration type angular velocity sensor, for example.

[0002]

2. Description of the Related Art Conventionally, as a vibration dynamic angular velocity sensor for driving a vibrator provided in a vibration angular velocity sensor, for example, one shown in a block diagram of FIG. 11 is known. As shown in FIG. 11, the displacement due to the vibration in the driving direction of the vibrator is output from the driving direction displacement detection electrode 81 to the displacement signal detection unit 82 as a displacement signal. The displacement signal output to the displacement signal detector 82 is synchronously detected by the synchronous detection circuit 83 at a timing synchronized with the displacement in the driving direction, and output to the amplitude adjuster 84 as vibration amplitude information. At the same time, the displacement signal output to the displacement signal detection unit 82 is additionally 90 deg phase shifted 85 and output to the amplitude adjuster 84 in order to facilitate the oscillation of the vibration type vibrator. By thus shifting the displacement signal output to the displacement signal detector 82 by 90 deg phase shift 85, the amplitude adjuster 84 generates an AC voltage component of the drive signal having a phase difference of approximately 90 degrees with respect to the displacement signal. is doing. The vibration amplitude information output to the amplitude adjuster 84 is the amplitude adjuster 8
When the vibration amplitude information is small compared with the amplitude setting value in 4, the AC voltage component of the drive signal having the increased adjusted amplitude is generated. On the other hand, when the vibration amplitude information is large, the AC voltage component of the drive signal having the reduced and adjusted amplitude is generated. In this way, the amplitude adjustment of the AC voltage component of the drive signal is for controlling the vibration driving force of the vibrator so that the vibration amplitude of the vibrator in the driving direction becomes constant. The AC voltage component of the drive signal whose amplitude has been adjusted in this way is output to the adder 86. This adder 86
In, the AC voltage component of the amplitude-adjusted drive signal and the DC voltage component (bias voltage) of the drive signal having a predetermined value are added to generate the drive signal. Then, the drive signal thus generated is applied to the drive electrode 87. The vibrator has a constant vibration amplitude in the driving direction due to the vibration of the electrostatic attractive force (vibration driving force) that is proportional to the square of the generated drive signal (applied voltage) and is generated between the vibrator. It is driven to vibrate.

[0003]

In the above-mentioned vibration type angular velocity sensor, since an AC signal having a driving frequency is externally applied to drive the vibration as described above, the signal for detecting the vibration state and the angular velocity of the sensor are detected. There is a problem that the drive signal is mixed with the signal to be detected. The component in which the AC signal as the drive signal is mixed has substantially the same frequency as the signal for detecting the angular velocity of the sensor, and therefore becomes an error when measuring the vibration state. Further, when the drive signal is mixed with the signal for detecting the angular velocity of the sensor, it becomes an offset of the sensor output.

In the vibration type angular velocity sensor, the driving voltage is lowered for the above reason to vibrate and drive the vibrator at the resonance frequency in the substantially driving direction, and the driving frequency and the resonance frequency in the angular velocity detecting direction are brought close to each other. The angular velocity detection sensitivity of the sensor is improved by increasing the displacement due to the Coriolis force. As described above, in the normal vibration type angular velocity sensor, the drive amplitude in the drive direction is controlled to be constant with respect to the temperature change.

Usually, the spring that determines the resonance frequency in the driving direction and the spring that determines the resonance frequency in the detection direction are made of the same material, and the ratio of spring constants is substantially constant with respect to temperature. Further, the ratio of the driving frequency in the direction of driving the vibrator and the resonance frequency in the direction of detecting the angular velocity is substantially constant, and the ratio of amplifying the displacement in the detection direction due to the Coriolis force is also substantially constant. However, when controlling the drive amplitude to be constant with respect to temperature changes, the Coriolis force was proportional to the speed in the drive direction with respect to changes in the drive frequency and the resonance frequency in the angular velocity detection direction due to temperature changes. Since the force is generated, the force proportional to the driving frequency is generated. On the other hand, the displacement of the angular velocity in the detection direction is inversely proportional to the spring constant in the detection direction, and the spring constant in the detection direction is proportional to the square of the resonance frequency in the detection direction. Therefore, when the resonance frequency of the drive and detection changes due to the temperature characteristic of the physical properties of the spring material due to temperature change, the displacement due to the Coriolis force in the detection direction is inversely proportional to the drive resonance frequency or the detection resonance frequency. However, the temperature characteristic of the detection sensitivity was deteriorated. Also, if the drive frequency varies due to variations in manufacturing conditions, it is necessary to separately adjust the angular velocity detection sensitivity of the sensor over a wide range only by adjusting the ratio of the resonance frequency in the conventional drive direction to the detection direction. The higher the signal, the smaller the detection signal, resulting in deterioration of the S / N ratio.

Therefore, the present invention has been made in view of the above problems, and provides means for reducing fluctuations in sensitivity due to temperature changes and variations in sensor sensitivity due to variations in resonance frequency of a vibrating body. This is a technical issue.

[0007]

In order to solve the above-mentioned problems, the invention of claim 1 is to provide a driving force applying means for vibrating and driving a vibrator, and a force generated by the driving force applying means for the vibrator. Drive signal generation having drive displacement detection means for detecting a displacement oscillated in response to the vibration, and amplitude adjustment means for controlling the drive signal output to the drive force application means based on the displacement signal detected by the drive displacement detection means. A vibration-type angular velocity sensor including a driving force applying unit and a driving frequency and a driving amplitude of the vibrator driven by the driving force applying unit. The drive amplitude of the control vibration type angular velocity sensor is set so that the ratio becomes constant.

According to the present invention, since the drive is controlled so that the ratio of the frequency and the drive amplitude of the vibrator driven by the drive force applying means becomes constant, the vibration amplitude of the vibrator in the drive direction is driven. The amplitude is proportional to the resonance frequency. The Coriolis force is proportional to the speed in the driving direction, and the driving speed is proportional to the driving amplitude. As described above, since the detection sensitivity is inversely proportional to the drive resonance frequency, the vibration type angular velocity sensor to which the present invention is applied does not depend on the drive frequency because the change in detection sensitivity due to the drive frequency is canceled by the change in drive amplitude. That is, since the sensitivity is stable with respect to the temperature change, the vibration type angular velocity sensor has a small variation in the sensor sensitivity with respect to the variation in the sensor element.

More preferably, as described in claim 2, the electrostatic force is used as the driving force by the driving force applying means, and the driving signal is composed of an alternating current component biased to a direct current component. The amplitude of the component is substantially constant, and by controlling the DC voltage of the drive signal, the drive force driven by the drive force applying means is controlled to control the vibration amplitude. And

Specifically, electrostatic attraction is used as the driving force by the driving force applying means. The drive signal is composed of an alternating current component biased to the direct current component, the amplitude of the alternating current component is substantially constant, and the direct current voltage of the drive signal is adjusted, so that it can be realized with a simple circuit configuration.

Further, according to a third aspect of the present invention, there is provided a vibration type angular velocity sensor drive device in which the phase difference between the displacement signal detected by the drive displacement detection means and the AC component of the drive signal is approximately 90 deg.

In the present invention, since the amplitude of the drive signal is controlled to be constant, the amplitude of the AC component of the drive signal is also constant. As a result, the drive signal mixed in the displacement signals in the drive direction and the detection direction becomes stable even if the Q value in the drive direction changes due to temperature changes or the like.

Further, since the AC component of the driving signal to be mixed is controlled to be constant, the fluctuation of the mixing amount of the driving signal into the displacement signal is suppressed, and the fluctuation of the zero point and the sensitivity is suppressed, so that it is highly accurate. A sensor can be realized.

According to a fourth aspect of the present invention, there is provided a vibration type angular velocity sensor drive device controlled so that the amplitude of a signal obtained by integrating the AC component of the displacement signal detected by the drive displacement detection means is constant.

Based on the displacement signal in the driving direction of the vibrator, the amplitude of the signal obtained by integrating the AC component of the displacement signal is controlled to be constant.

According to a fifth aspect of the present invention, the vibration type angular velocity sensor driving device is such that the set value of the amplitude of the AC component of the displacement signal detected by the driving displacement detecting means is proportional to the driving frequency.

A voltage is generated in which the drive frequency is proportional to the set value of the amplitude of the AC component of the displacement signal detected by the drive displacement detection means. The driving signal is adjusted in order to change the driving force so that the ratio of the generated voltage and the voltage proportional to the driving amplitude of the displacement signal becomes constant.

According to a ninth aspect of the present invention, the drive signal is a drive device of a vibration type angular velocity sensor which outputs two signals which are a pair of which the AC components are inverted from each other.

As described above, the drive signal 2
Since the outputs are paired and their AC components are inverted from each other, unnecessary force is canceled and noise is also canceled.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. First, the vibration gyro sensor element of the angular velocity sensor will be described. FIG. 12 shows an example of a vibration gyro sensor element used in the vibration type angular velocity sensor of the present invention. Movable part 2 formed on substrate 18 of sensor element
Reference numeral 5 is a conductor or semiconductor made of amorphous, polycrystalline, or single crystal, and includes a drive electrode 27, a drive displacement electrode 9 and an angular velocity detection electrode 10, and is provided on the substrate via the beam 26 and the anchor 8. It is held with a gap in between. The movable portion 25 is displaceable in the drive direction (X direction in the drawing) and the detection direction (Y direction in the drawing), and the ratio of the resonance frequency in the detection direction to the resonance frequency in the drive direction is slightly higher than 1. . Usually, the beam that determines the spring constant in the driving direction of the vibrator and the beam that determines the spring constant in the angular velocity detection direction are made of the same material. Therefore, even if the physical properties of the material change due to temperature changes and the resonance frequency in the driving direction and the detecting direction also change, the ratio of the spring constants in the driving direction and the detecting direction hardly changes. Further, the ratio of the resonance frequency in the drive direction to the detection direction hardly fluctuates. Therefore, if the Q value of resonance in the detection direction is sufficiently higher than the amplitude amplification factor, the amplitude amplification factor will be stable with respect to temperature changes. The sensitivity for detecting the angular velocity is determined by the amplitude of the vibrator for detecting the angular velocity in the driving direction, the spring constant in the angular velocity detecting direction, and the amplitude amplification factor in the detecting direction. The amplitude amplification factor in the angular velocity detection direction is determined by the ratio between the resonance frequency in the detection direction and the drive frequency of the vibrator, and the Q value in the angular velocity detection direction. If it is sufficiently large, it can be considered that it is determined by the ratio of the resonance frequency in the angular velocity detection direction and the driving frequency of the vibrator. In the following description, unless otherwise specified, “detection” is synonymous with “angular velocity detection” and “driving the transducer” is abbreviated as “driving”.

In the sensor section of this angular velocity sensor, the frequency, phase and amplitude of the AC component of the drive signal are adjusted based on the displacement signal in the drive direction and supplied to the drive electrodes of the sensor section. At this time, the movable section 25 of the sensor section is driven in the drive direction by the supplied drive signal, and the driven displacement is returned to the drive circuit via the drive direction displacement detection electrode 5 and the displacement signal detection section 6, and driven. It is driven at a resonant frequency in the direction with the amplitude adjusted. In FIG. 1, the output of the displacement signal detector 41 has its phase adjusted as a drive signal by an amplitude adjuster 44, and the displacement signal in the drive direction detected in FIG. A coefficient inversely proportional to the frequency is multiplied. On the other hand, the displacement signal becomes a rectangular wave with a duty of approximately 50% in synchronization with the displacement signal in the timing signal generator 48, and the phase is shifted by 90 deg. By synchronously detecting the output of the integrating circuit by the 90 deg phase-shifted timing signal, a voltage proportional to the amplitude of the output of the integrating circuit 42, that is, a value proportional to the value obtained by dividing the displacement signal by the driving frequency is output. Synchronous detection 4
The output of No. 3 and the amplitude setting value are compared by the amplitude adjuster 44, and the amplification factor for adjusting the amplitude of the AC component of the drive signal is output so that the output of the synchronous detection 43 matches the amplitude setting value. Then, a predetermined DC voltage component is added as a bias voltage to the AC component of the drive signal, which is the product of the output of the integration circuit 42 and the amplification factor, and the drive signal is supplied to the drive electrode 13. Separately, in the memory 50, the relationship between the drive frequency and the temperature at which the ratio between the resonance frequency in the detection direction and the drive frequency is constant is recorded using the temperature characteristic of the resonance frequency in the detection direction as basic data. The temperature sensor 49 detects the temperature of the vibrator or the vicinity of the vibrator, and the temperature sensor 4
Based on the temperature detected at 9, the memory 50 outputs frequency information for driving the vibrator to the oscillator 51. Then, the oscillator 51 generates an AC component of the drive frequency based on the information from the memory 50. On the other hand, as described above in part, the displacement signal in the driving direction is a signal in which only the AC component is integrated by the integrator circuit 42 and the displacement signal is multiplied by a 1 / frequency coefficient, and this signal is synchronously detected. It is used as amplitude information of the output of the integrating circuit 42. Next amplitude controller 4
In 4, the same amplitude information is compared with the amplitude setting value, and when the vibration amplitude information is small, the AC voltage component of the drive signal having the increased and adjusted amplitude is generated, while the same vibration amplitude information is large. In that case, an alternating voltage component of the drive signal having a reduced adjusted amplitude is generated. The multiplier 45 multiplies the output from the amplitude adjuster 44 and the AC signal output from the oscillator 51 to generate the AC component of the amplitude-adjusted drive signal. By applying this drive signal to the drive electrode 13, it becomes possible to perform drive in which the drive amplitude is controlled.

By making the ratio of the drive frequency to the resonance frequency in the detection direction constant as described above, the amplitude amplification factor in the detection direction becomes constant. The displacement signal in the driving direction is integrated and then synchronously detected, and the amplitude after the synchronous detection becomes constant, so that the driving amplitude is proportional to the driving frequency. The speed of the vibrator in the driving direction is proportional to the square of the driving frequency, and the Coriolis force is proportional to the speed in the driving direction, so that the Coriolis force is proportional to the square of the driving frequency. On the other hand, the spring constant in the detection direction is proportional to the square of the drive frequency because the ratio between the drive frequency and the resonance frequency in the detection direction is constant. As described above, even if the resonance frequency in the detection direction of the vibrator fluctuates due to temperature change, the amplitude amplification factor is constant, so the angular velocity detection sensitivity is stable with respect to temperature change. As a result, the drive is controlled so that the amplitude of the output of the integrating circuit is constant, and thus the vibration amplitude in the drive direction becomes an amplitude proportional to the drive resonance frequency. In the vibration type angular velocity sensor to which the present invention is applied, the fluctuation of the detection sensitivity due to the driving frequency is canceled by the fluctuation of the driving amplitude, so that it does not depend on the driving frequency. That is, since the sensitivity is stable with respect to the temperature change, the vibration type angular velocity sensor has a small variation in the sensor sensitivity with respect to the variation in the sensor element. 2, in the memory 50 of FIG. 1, the driving frequency with respect to the temperature and the data of the driving amplitude proportional to the driving frequency are recorded in the memory 52,
Drive control may be performed based on this data. More memory 5
The configuration of 2 eliminates the need for the integrating circuit 42 in FIG. 1 and reduces errors in amplitude control due to low-frequency noise amplified or mixed in the integrating circuit. When the vibrator is driven by using electrostatic attraction, the driving force is controlled by adjusting the bias voltage in which the amplitude of the AC component of the driving signal is constant in FIG. 3 and FIG. 4 to control the driving amplitude. May be. With the above configuration, the AC signal component of the drive signal mixed in the angular velocity detection signal is reduced through the parasitic capacitance between the angular velocity detection electrode and the drive electrode, etc., so that the offset fluctuation of the sensor output can be reduced. Performance can be improved. Next, another embodiment of the present invention will be described with reference to the block diagram of FIG. In FIG. 1, the temperature sensor detects the temperature of the sensor or in the vicinity of the sensor and the temperature is controlled based on the information. In FIG. 5, the product of the output of the integration circuit 62 and the amplification factor of the amplitude adjuster 66 is used. A predetermined DC voltage component is added as a bias voltage to the AC component of the drive signal and is supplied to the drive electrode 13. As a result, drive control is performed so that the amplitude of the output of the integrating circuit becomes constant. As a result, the vibration amplitude becomes an amplitude proportional to the drive resonance frequency. In FIG. 6, in the embodiment of FIG. 5, a timing signal is generated by a displacement signal in the driving direction, and the phase of the timing signal is 90 de by a phase shifter.
Although the phase is shifted by g to obtain the timing signal for synchronous detection, in FIG. 6, the timing signal for synchronous detection is generated from the output of the integrating circuit. As a result, the circuit configuration can be simplified, and the cost of the configuration circuit can be reduced. In FIG. 7, the AC component of the driving signal is generated by amplifying or attenuating the output of the integrating circuit, the amplitude adjuster (AGC) generates a driving bias voltage, and the adder generates the driving bias voltage and the driving signal. A driving signal is generated by adding AC components. Since the drive circuit of the present invention is controlled so that the amplitude of the output of the integrating circuit is constant, the amplitude of the AC component of the drive signal is also constant. As a result, the drive signal mixed in the displacement signals in the drive direction and the detection direction becomes stable even if the Q value in the drive direction changes due to temperature changes or the like. The drive signal mixed in the displacement signal in the drive direction and the detection direction becomes an error component, and in particular, when the amount mixed in the displacement signal in the detection direction changes, the zero point changes and the sensor characteristics deteriorate. The fluctuation of the mixing amount of the driving signal into the displacement signal in the driving direction causes the fluctuation of the timing of the synchronous detection of the detection signal, which causes the fluctuation of the sensitivity and the deterioration of the sensor performance. According to the embodiment shown in FIG. 3, since the AC component of the mixed drive signal is controlled to be constant, the variation of the mixed amount of the drive signal into the displacement signal is suppressed, and the variation of the zero point and the sensitivity is suppressed. Therefore, a highly accurate sensor can be realized. In FIG. 8, based on the displacement signal in the driving direction, a voltage proportional to the driving frequency is generated by the F / V converter, and the generated voltage is amplified or attenuated to obtain a reference proportional to the driving frequency. A voltage is generated and the displacement signal is synchronously detected to generate a voltage proportional to the drive amplitude, and the bias voltage of the drive signal is adjusted in order to change the drive force so that it matches the above reference voltage. Is added and the bias voltage of the drive signal is added to generate the drive signal. As a result, the same effect as that of the embodiment of FIG. 7 can be obtained. In FIG.
Based on the displacement signal in the driving direction, a voltage proportional to the driving frequency is generated by the F / V converter, and the ratio between the voltage proportional to the driving frequency and the voltage proportional to the driving amplitude by synchronously detecting the displacement signal. The bias voltage of the drive signal is adjusted in order to change the drive power so as to keep constant. Separately, the displacement signal that has passed through the displacement signal detector is integrated, amplified, or attenuated, and the AC component of the drive signal and the bias voltage of the drive signal are added to generate the drive signal. Next, an embodiment of an amplitude adjuster of a drive circuit to which the present invention is applied is shown in FIGS. 13, 14 and 15 using block diagrams. In FIG. 13, a voltage proportional to the difference between the synchronously detected vibration amplitude signal and the amplitude setting value is output as the bias voltage. As a result, the phase delay of the driving force is suppressed, and control with good responsiveness becomes possible. In FIG. 14, a voltage proportional to the time integral value of the difference between the drive amplitude signal and the amplitude setting value is output as the bias voltage. As a result, the difference between the drive amplitude signal and the amplitude setting value is controlled to be zero, and accurate control is possible. In FIG. 8, the sum of the voltage proportional to the time integral value of the difference between the drive amplitude signal and the amplitude setting value and the voltage proportional to the difference between the drive amplitude signal and the constant amplitude value is output as the bias voltage. As a result, responsiveness and accurate control are possible. FIG. 10 shows a block diagram of an embodiment of a drive circuit to which the present invention is applied. A drive signal in which the inverted AC component is superimposed on the same bias potential with respect to the drive circuit of FIG. 7 is generated, and the drive signal is inverted as a drive signal mixing source by supplying the drive signal to the electrode where the electrostatic attraction acting on the vibrator is opposite. The signals cancel each other out, and it is possible to reduce drive signals mixed in as compared with the case of FIG. 7. Further, by making the drive electrodes the same in configuration with respect to the drive signal that is inverted, the force component that works in proportion to the square of the AC component and the force component that works in proportion to the square of the DC voltage cancel each other out. It is possible to reduce unnecessary movement. FIG. 13 shows a block diagram of an embodiment of a drive circuit to which the present invention is applied.
As a drive signal mixing source, the drive circuit of FIG. 6 generates a drive signal in which an inverted AC component is superimposed on the same bias potential and supplies the drive signal to the electrode where the electrostatic attraction acting on the vibrator is opposite. The inverted signals cancel each other out, and it is possible to reduce drive signals mixed in as compared with the case of FIG. Further, by making the drive electrodes the same in configuration for the drive signal that is inverted, the force component acting in proportion to the square of the AC component and the force component acting in proportion to the square of the DC voltage are canceled out. Therefore, it is possible to reduce unnecessary movement.

A charge amplifier may be used in the first stage of the displacement signal detecting section. Further, the AC component of the drive is formed by integrating the displacement signal in the embodiment, but in FIG. 5, FIG. 6, FIG. 7, FIG. 10 and FIG. The AC component of may be generated.

Although not described with reference to FIG. 12 and the embodiment, the vibration of the movable part 25 having the tuning electrode and tuning circuit for adjusting the resonance frequency in the detection direction and the moving part side detection electrode 10 during driving. The sensor performance can be improved by adding a servo electrode and a servo circuit for adjusting the direction.

[0025]

According to the present invention, since the drive control is performed so that the amplitude of the output of the integrating circuit is constant, the vibration amplitude in the drive direction becomes an amplitude proportional to the drive resonance frequency. The Coriolis force is proportional to the speed in the driving direction, and the driving speed is proportional to the driving amplitude. As described above, since the detection sensitivity is inversely proportional to the drive resonance frequency, the vibration type angular velocity sensor to which the present invention is applied does not depend on the drive frequency because the change in detection sensitivity due to the drive frequency is canceled by the change in drive amplitude. That is, since the sensitivity is stable with respect to the temperature change, the vibration type angular velocity sensor has a small variation in the sensor sensitivity with respect to the variation in the sensor element. Since the drive circuit of the present invention is controlled so that the amplitude of the output of the integrating circuit is constant, the amplitude of the AC component of the drive signal is also constant. As a result, the drive signal mixed in the displacement signals in the drive direction and the detection direction becomes stable even if the Q value in the drive direction changes due to temperature changes or the like. Since the AC component of the mixed drive signal is controlled to be constant, the variation of the mixed amount of the drive signal into the displacement signal is suppressed. Further, since the zero point and the fluctuation of the sensitivity are suppressed, highly accurate sensor control can be realized.

[Brief description of drawings]

FIG. 1 is an example of a drive circuit according to an embodiment of the present invention.

FIG. 2 is an example of a drive circuit according to an embodiment of the present invention.

FIG. 3 is an example of a drive circuit according to an embodiment of the present invention.

FIG. 4 is an example of a drive circuit according to an embodiment of the present invention.

FIG. 5 is an example of a drive circuit according to an embodiment of the present invention.

FIG. 6 is an example of a drive circuit according to an embodiment of the present invention.

FIG. 7 is an example of a drive circuit according to an embodiment of the present invention.

FIG. 8 is an example of a drive circuit according to an embodiment of the present invention.

FIG. 9 is an example of a drive circuit according to an embodiment of the present invention.

FIG. 10 is an example of a drive circuit according to an embodiment of the present invention.

FIG. 11 is an example of a drive circuit according to an embodiment of the present invention.

FIG. 12 is an example of a vibration gyro sensor element to which the present invention is applied.

FIG. 13 is an example of an AGC section of a drive circuit to which the present invention is applied.

FIG. 14 is an example of an AGC section of a drive circuit to which the present invention is applied.

FIG. 15 is an example of an AGC section of a drive circuit to which the present invention is applied.

FIG. 16 is an example of a drive circuit to which the present invention is applied.

[Explanation of symbols]

5: Driving direction displacement detection electrode 6: Angular velocity detection direction displacement detection electrode 7: Driving force application electrode 8: Anchor (connection part between beam and substrate) 9: Movable part side drive displacement detection electrode 10: Movable part side angular velocity Detection electrode 13: Electrode 14: Electrode pad of fixed electrode for detecting displacement in angular velocity detection direction 15: Electrode pad of fixed electrode for detecting displacement in drive direction 16: Fixation for applying force in drive direction Electrode electrode pad 17: Wiring connecting fixed electrode and electrode pad for applying driving force 18: Substrate 25: Movable part 26: Beam

Claims (9)

[Claims] 1. A driving force applying means for driving an oscillator to vibrate, a driving displacement detecting means for detecting a displacement in which the oscillator vibrates by receiving a force from the driving force applying means, and the driving displacement detecting means. Drive signal generating means having an amplitude adjusting means for controlling the drive signal output to the drive force applying means on the basis of the displacement signal detected by, and angular velocity detection for detecting the displacement of the vibrator in the angular velocity detecting direction due to the Coriolis force. A vibration type angular velocity sensor comprising: a vibration type angular velocity sensor including: a vibration type angular velocity sensor including: Driving device for angular velocity sensor. 2. An electrostatic attractive force is used as the driving force by the driving force applying means, the driving signal is composed of an alternating current component biased by a direct current component, and the amplitude of the alternating current component is substantially constant in the previous period. 2. The drive device for a vibration type angular velocity sensor according to claim 1, wherein the drive force driven by the drive force applying means is controlled by adjusting the DC voltage of the control means to control the vibration amplitude. . 3. The phase difference between the displacement signal detected by the drive displacement detection means and the AC component of the drive signal is approximately 90 deg.
The drive device for the vibration type angular velocity sensor according to claim 1 or 2, characterized in that 4. The control according to claim 1, wherein the amplitude of a signal obtained by integrating the AC component of the displacement signal detected by the drive displacement detecting means is constant.
The drive device for the vibration type angular velocity sensor according to any one of 1. 5. The vibration according to claim 1, wherein the set value of the amplitude of the AC component of the displacement signal detected by the drive displacement detection means is proportional to the drive frequency. Driving device for mold angular velocity sensor. 6. The method according to claim 1, wherein the DC voltage of the drive signal or the amplitude of the AC component of the drive signal varies in proportion to the difference between the vibration amplitude and the set amplitude. The drive device of the vibration type angular velocity sensor described in (1). 7. The DC voltage of the drive signal or the amplitude of the AC component of the drive signal fluctuates in proportion to a value obtained by time-integrating the difference between the vibration amplitude and the set amplitude. The drive device for the vibration-type angular velocity sensor according to claim 5. 8. The amplitude of the DC voltage of the drive signal or the AC component of the drive signal is the sum of a value obtained by time-integrating the difference between the vibration amplitude and the set amplitude and a value proportional to the difference between the vibration amplitude and the set amplitude. The drive device for the vibration type angular velocity sensor according to any one of claims 1 to 5, wherein the drive device varies in proportion. 9. The drive of the vibration type angular velocity sensor according to claim 1, wherein the drive signal outputs two signals forming a pair in which alternating current components thereof are inverted from each other. apparatus.